Method of making tire chains



March 14, 1933.

M. R. WELLS METHOD OF MAKING TIRE CHAINS Original Filed Dec. 15 1930 4Sheets-Sheet l March 14, 1933. Y M R WELLS H Y 1,901,213

METHOD OF MAKING TIRE CHAiNS Original Filed Dec. 15, 1930 4 Sheets-Sheet2 March 14, 1933. M, R W L 1,901,213

METHOD OF MAKING TIRE CHAINS Original Filed Dec. 15, 1930 4 Sheets-SheetC:

gnw'ntow March 14, 1933. M. R. WELLS METHOD OF MAKING TIRE CHAINSOriginal Filed Dec. 15, 1930 4 Sheets-Sheet 4 gjwuantoz Awa P!LOT SNAPSINTO LINK Patented Mar. 14, 1933 UNITED STATES PATENT OFFICE MERRITT n.WELLS, or cLnvnLAnn, omo, ass eivon, BY -MESN'E nssremmmrs, TO THE McKAYCOMPANY, or PITTSBURGH, PENNSYLVANIA, a concurrent or PENNSYLVANIAMETHOD OF MAKING TIRE-CHAINS Original application filed December 15,1930, Seria1 No. 502,362. Divided and this application filed September3, 1931.

This invention relates to a method for electrically welding metal partstogether, and particularly by a weld of the resistance type. Theinvention is more specially concerned with a method of welding lugs tolinks of a chain, and is a division of my application for Letters Patenton an electric welding machine, "Serial No. 502,362, filed December15th, 1930.

Anti-skid tire chains for automobiles have long been in use, and havegenerally comprised a series of groups of cross links, the ends of whichare usually hooked to a pair of circumferential bands or chains. Varioustypes and kinds of cross links have been used, and it has been foundthat a very successful type is one having a plurality of chain links, tosome of which are secured small lugs, which lugs are arranged to coactwith the road sur' face, thereby providing additional traction to thewheels and preventing unnecessary skidding.

One of the objects of the present invention is to provide a method ofmanufacturing short chain sections, having links provided withprojecting lugs and having attaching devices at the ends of thesections, so

that the sections may be effectively used as the cross members of a tirechain, and Iaccomplish this result by welding lugs to some of the linksof a continuous chain and thereafter severing portions of said chain andsecuring fastening devices to the extreme links of the severed portions.

Another object of the invention is to provide a method for automaticallyplacing the lugs on a chain and welding them thereto in a manner whichwill greatly decrease the cost of manufacture of the chain, and at thesame time insure a far better weld between the lug and'the links.

Another object is to provide a method of producing groups of luggedlinks alternated with groups of plain links in a continuous chain, whichis thereafter severed through Serial No. 560,970.

certain plain links to produce individual sec plain links, and theattachment of the fastening devices to the end links of the sections,which are plain, enables the production of the desired form of crosschain.

More specifically, an object of this invention is to provide a methodwhich comprises welding lugs to groups of links in a chain being fed,and thereafter feeding a group of links without theattachment of lugs,the feeding of such unlugged groups being in a cycle corresponding tothe feeding of one link having lugs; so that the chain, with alternategroups of lugged and unlugged links, may be produced quickly andeconomically. This method provides for varying the number of lugs andunlugged links as desired,

there being preferably an odd number of unlugged links in the group. Inmaking a cross chain section from such continuous chain, I sever thecontinuous chain through the middle unlugged link of a group and applyattaching devices to the terminal unlugged link of the severed section.

The embodiment of the apparatus illus trated in the drawings hereof issubstantially the same as that shown in my prior application, theconstruction being such as will carry out my method successfully. Thisapparatus comprises means for feeding a continuous length of chain to asuitable welding mechanism, to which individual lugs are fed, preferablya pair at a time, and placed in position on top of a'link of the chain;means for simultaneously welding the pair of lugs to the diagonallyopposite corners of the link, the chain being then advanced a distanceof one link and the operation repeated until the desired number oflugged links has been provided; and means for then feeding at oneoperation a plurality of links of the number desired for unl'ugged linksin the chain plus one, and then applying lugs to the last link of thisgroup which becomes the first link of the next lugged group. Thereafter,I sever the chain in the region ofthe unlugged portion into smallsections, which constitute the main portion of the cross chain membersof the tire chain. These cross chains thus comprise a central portionhaving links to which lugs have been welded, and end portions which haveno lugs. Hooked links are then secured to the ends of such cross chains,and the chains are put in place on circumferential bands or chains whichconstitute the retaining means to keep the chain in place on the tire.

This invention will become apparent from the following description,referring to a preferred mechanism used in carrying out my improvedmethod, and which is illustrated in the drawings. The essential novelfea tures of the method will be set forth in the claims.

In the drawings, Fig. 1 is a plan of chain used in forming the crosschain; Fig. 2 is a plan of the chain having lugs welded on links atspaced intervals; Fig. 3 is a view of the chain shown in Fig. 2, afterit has been separated into short cross chain sections; Fig. 4 is a planof a complete cross chain; Fig. 5 illustrates the chain in use; Fig. 6is a. side elevation of a section of a chain having the lugs weldedthereon; Fig. 7 is a transverse section through a lugged portion of thechain; Figs. 8 and 9 are substantially vertical sections, through anapparatus capable of carrying. out my improved method; Fig. 10 is asectional detail, as indicated by the lines 1010 on Fig. 8; Fig. 11 isan enlarged detail of the, welding table in which the chain is heldduring the welding operation; Figs. 12 and 13 are detailed sections onan enlarged scale of the welding table, as indicated by the lines 1212and 1313, respectively, on Fig. 11; Fig. 14 is a horizontal section,illustrating the electrode arm and its mounting as indicated by thelines 1414 on Fig. 9; Fig.

' 15 is a sectional detail, taken substantially along ofi'set lines 1515on Fig. 9; Fig. 16 is a diagram and illustrates the timing of thevarious steps of mymethod and the order of movements of the mechanismfor one cycle of operation.

My improved method for making cross chains for tire chains comprisesfeeding a continuous chain of plain connected links, a distance of onelink,- and applying a pair of lugs to opposite corners of the link sofed, thereafter electrically welding such lugs simultaneously to thelink and repeating the operation for successive links. Then, after apredetermined number of consecutive links have had lugs welded to them,I feed the chain a distance covering one more link than is req'uired forthe number of unlugged links.

This last feed is effected in a cycle of operations, corresponding toeach of the preceding cycles. I then weld a pair of lugs onto oppositecorners of the last link of the group, which last link becomes the firstlugged link of the next succeeding group and leaves a predeterminednumber of plain links between this group and the preceding group.

As a subsequent operation, I sever the chain in an intermediate link ofthe plain -gro up, and so produce'short chains, each havinganintermediate group of lugged links and one or more plain links at eachend thereof. Thereafter I apply attaching devices to the terminal plainlinks of such short chains. The chains are then secured to the usualcircumferential chains, which act to bind my cross chains together foruse.

In the drawings, I have shown an apparatus arranged to carry out myimproved .method. This apparatus comprises, as shown, a main frame 10,arranged to support the different units of the welding mechanism,namely, a power shaft, a chain feed unit, a lug feed unit, a weldingbed, and an electrode assembly. The frame 10 comprises a tablelikestructure supported by suitable legs 12, and provided with cross frameor bracing members 14, to act to the rigidity of the structure.

The chain to which the lugs are to be welded is supplied insubstantially continuous lengths and may be stored in suitablecontainers, (not shown). The chain passes upwardly from a containerthrough a guide loop 15, carried by a bracket 17 adjacent one side ofthe frame, and passes over'a pulley 18, journalled on a shaft 19,carried by such bracket. From the pulley 18 the chain passes over asuitable grooved guideway 20, and is held in contact therewith by a fiatspring 21. From the guideway 20 the chain passes across the machine to awelding bed 22, which is mounted on top of the machine adjacent the lefthand side, as shown in Figs. 8 and 9. This-welding bed is provided withsuitable guideways, and lug feeding means, hereinafter described, andhas a flanged guide member 23, which extends from the bed to theleft-hand side of the machine, and acts to carry the chain to a positionto drop into a suitable container arranged to store the lugged chain.The arrangement is such that the stretches of chain which overhang themachine on, opposite sides will hold the chain taut over the weldingbed, which is raised slightly above the top of the machine.

In carrying out my improved method, the chain is fed across the tablefrom right to left, (Figs. 8 and 9) by a suitable feeding arm or lever25, which feeds a link, or. a predeten mined-number of links, asdesired, across the welding bed 22, in each cycle of operation of themachine. The feeding arm 25 is pivoted on a cross shaft 26, journalledin a bracket 27 carried by the base 28 of the machine. Adjacent theupper end of the lever or arm 25 is a channel shaped shoe 28, arrangedto guide the chain on the lever. shoe 28 is interposed between thepulley 18 and the welding bed 22,-and engages the chain at all times.

The chain is gripped for feeding by a pawl 29, which is pivotallymounted in a slot formed in the-shoe and is arranged to enter the linksof the chain C. When the arm 25 is drawn to the rear, the pawl 29 iswithdrawn from engagement with the chain by a suitable friction device.Such device is best shown in Figs. 8 and 10, and comprises a shoe 30,carried in a stud 31, which is pivoted to a rearwardly extending arm 29of the pawl. The shoe is held in engagement with a rod 32, by a suitablecompression spring 33, carried in the stud. The rod 32 is pivoted at 34to a bracket 35, secured to the frame, some distance to the right of thelever 25. The construction just described (from the position shown inFig. 8) the pawl 29 is rocked counter-clockwise, thereby withdrawing thenose of the pawl from engagement with the chain. The pawl is maintainedin this withdrawn position until the lever starts to swing in a reverseor forward direction, towards the left, (to the position shown in Fig.8), at which time the pawl is rocked clockwise, thereby causing the nose-thereof to enter a link in the chain and carry it forward with thelever 25.

The lever 25 is swung by a cam 36 through the medium of a roller 37which is carried by a lever 38, having a resilient connection 39, withthe arm 25. This resilient connection permits the forward stroke of thelever to be adjusted by a threaded stud 40, mounted in a latch 41,pivoted to the welding bed 22, and serving a purpose hereinafter to bedescribed. The position of this stud 40 is such that the lever 25 willstrike it on its forward or left The hand stroke and arrest its movementto carry the chain forward to a predetermined position.

The arrangement of the mechanism is such that I may weld lugs on aselected number of consecutive links and then skip a selected number oflinks, and so on. My improved method contemplates feeding the chain alink at a time, until suflicient lugged links have been fedconsecutively to care for the predetermined number of lugged links, andthen feeding, at one cycle of operation, of the feeding mechanism, aplurality of links, the last one of which becomes the first of thesucceeding group of lugged links. This feeding operation describedallows the welding operation to be performed by my improved method at ahigh rate of speed, as it permits it to be carried on at every cycle ofoperation of the machine, there being no extra cycle to feed the severallinks which. do not require lugs to be welded thereon. This isaccomlished by providing a variable rearward imit for the feeding arm25, as about to be described.

In the embodiment illustrated, the feeding arm 25 is positively drivenin a feeding direction by the cam 36, but is returned by a spring 140,one end of which is secured to the arm 25 and the other to a suitableframe member. The spring also causes the roller 37 to be normallmaintained in contact with the cam 36. hen the links are fed one at atime, a pawl 141, pivoted to the lever, engages a suitable stop 42,carried by a frame member and prevents further rearward movement of thelever. However, when a plurality of links are to be fed, the stop 42 isautomatically withdrawn and the arm 25 moves to the rear (to the rightin Fig. 8), beyond the normal position of the stop 42 and engage a stop43, which is adjustably carried by a suitable frame member 44. p

The arrangement of the stop 42 is such that it is automaticallywithdrawn when a predetermined number of links have had lugs weldedthereon. To this end the stop is pivoted to a stud 45, carried by theframe member 44, and is provided with a downwardly extending arm 46, towhich is pivoted a link or plunger 47. The plunger 47 is slidablymounted in a bearing member 48, carried by the frame member 44 and itsrearmost end is arranged to contact with the periphery of a cam disc 50.A suitable spring 52, secured to the arm 46 of the stop 42 normallymaintains the contact between the plunger 47 and the cam 50.

In the construction shown, the periphery of the cam 50 is provided withtwo notches, 53 and 53a, and as the disc is rotated, as will hereinafterbe described, the notches are presented to the plunger and the spring 52carries the plunger rearwardly, thereby swinging the stop 42 about itspivot, permitting the passing of the pawl 141 over the stop 42 andbringing the arm 25 into contact with the,

stop 43.

A suitable indexing mechanism is provided to rotate the cam disc 50.Referring to Fig. 8 and Fig. 15, the disc 50 is rigidly mounted on ashaft 51, rotatably carried by a bracket 56, secured to the frame member44 by suitable bolts 57. Rigidly secured to the shaft 51 is a rachetwheel 58, which is arranged to be rotated by a pawl 59, carried by anarm 60, journalled on the shaft 51. The arm 60 is pivotally mounted ontheshaft 51 and is swung back and forth to feed the ratchet by a lever62. This lever is pivoted to the arm 60 as at 63, and carries, on itslowermost end, a cam ring 64, arranged to embrace a disc cam 65, whichis rigidly secured to the main driving shaft 1.

The construction is such that the ratchet 58 is caused to be moved apredetermined number of teeth for each cycle of operation of themachine, so that the links may be fed,

one at a time, for a predetermined number of cycles, and then aplurality of links fed at one cycle. If, for example, three links are tobe fed consecutively, it. is apparent that because there are twooppositely disposed notches in the cam disc 50, the ratchet wheel mustbe given one-sixth of a rotation. I determine the amount of the feed ofthe ratchet 58 by providing a guard 65, which is adjustable about theaxis of the ratchet wheel and serves to withdraw the pawl at apredetermined point on the rear stroke thereof.

The parts, as shown in Figs. 8 and 9, are in a position to have a lugplaced upon the first lug-link of a three-link group. The plunger 47 haspassed from the notch 53 by an angular, distance of 60 degrees. On thefirst cycle of operation, the lugs are welded on the link so positioned,and as the lever 25 advances to feed the next link, the ratchet 58 isagain advanced 60 degrees to a position where the plunger is 120 degreesfrom the notch 53, the guard being retained in the position shown inFig. 9, by a pin 68. The lugs are now welded on the second link, and thereturn or non-feeding movement of the lever 25 is stopped by the member42, which permits it on its next forward movement to feed only one linkas before. Simultaneously, with this next feeding movement, the ratchet58 is advanced an additional 60 degrees. Lugs are now welded on thislink, making three consecutive links with lugs welded thereon.

The ratchet has now been advanced 180 degrees. At this period theplunger 47 has entered the recess or notch 53a, which is spaced 180degrees from the notch 53, thereby causing the spring 52 to withdraw thestop 42 from the path of the pawl 41 and permit the spring 140 to returnthe lever 25 beyond the stop 42 into engagement with the stop 43.

. In the setting shown in the drawings, the stop 43 ispositioned so asto permit the lever 25 to pick up six links and feed them across thewelding table, bringing the sixth link to a position to have lugs weldedthereon. This feeding movement will advance the ratchet 60 degrees fromthe notch 53a, thereby bringing the stop 42 again into active positionand the parts to substantially the same relative position as shown inFig. 8.

Immediately after the chain has been fed to the welding table, it isaccurately positioned so that the lugs may be placed thereon in properrelationship to the links. This is accomplished by a pilot member 70,best shown in Figs. 8 and 9. The pilot 7 0 comprises a bar slidablymounted in a vertically extending slot in the frame of the welding table22. The upper portions of the pilot bar is of such a shape aswill-conveniently enter the link in a chain, and the upper cornersthereof are bevelled, so as to guide the link and position it on thepilot head, thereby accurately aligning it.

The pilot is operated, or reciprocated in an up and down movement, by acam 72, rigidly secured to the main drive shaft 1, and which rotateswithin a ring portion 73 of a beam 74, the rearmost end of which ispivoted to a link 75, which in turn, is pivoted to a bracket 76, carriedby the base 28 of the frame. The forward or left-hand portion 7 6 of thebeam 7 4 carries a pivot pin 77, through which a link or rod 78 isslidably mounted. The uppermost end of the rod 78 is pivoted as at 79 tothe lowermost end/of the pilot bar 70. Intermediate its ends the rod 78has a fixed collar 80, between which collar and the pivot pin 77 is acompression spring 81, which normally acts'to retain the bar 70 is anuppermost position. As the arm 76 of the beam is rocked to a lowermostposition, the pivot pin coacts with a nut 82 on the rod and positivelywithdraws it downwardly.

The pilot bar 7 0 is normally locked in a downward position by the latch41, heretofore mentioned. The latch 41 is pivoted at 85 to the frame 22and has a nose arranged to normaly be held in engagement with a notch 86of the plunger'70 by a spring 87. At such time as the lever 25 nears theend of its feeding stroke (to the left in Fig. 8) it contacts with thestop pin 40, previously mentioned, and swings the latch into anon-engaging position, thereby permitting the spring 81, which haspreviously been compressed by the upward movement of the beam 76 to snapthe pilot bar 70 upward through the link with comparatively great speed.

The welding table 22 comprises a bed 90, Figs. 11 to 13, on which ismounted, by suitable bolts. a guide block 91, through which is cut achannel 92, arranged to serve as a guide for the chain, and into whichchannel the pilot 7 0 projects and engages the chain.

After the pilot 70 has positioned a link, the lugs indicated at L in thedrawings are fed by suitable means, hereinafter described, whichsuperimposes the lugs upon opposite or diagonal corners of the links, asillustrated in Fig. 11. Electrodes of respectively opposite polarity arethen brought into contact with, the lugs and a welding current applied,thereby simultaneously welding both lugs to the link. The link itselfcarries the current from one weld to the other.

In the embodiment shown in Figs. 9 and 14 there are two electrodes 100and 101, mounted in substantially vertical slots in electrode carriers102. The carriers 102 are separated from each other by a suitableinsulation and are likewise insulated from their mounting arms 104. Thearms 104, the electrodes 100 and101, and carriers 102 are retainedtogether in the unit by suitable bolts 105, which pass through the armsand carriers and are insulated therefrom by a suitable insulating sleeve106. Thus it will be seen that the electrodes are insulated from eachother, as well as from the various supporting mechanisms. The electriccurrent is carried to the electrode carriers by flexible laminatedstraps 107, which are connected to the opposite poles of the secondarywinding of a transformer unit 108, the primary winding 109 of which isconnected to a suitable source of current supply 110. If desired, theelectrode carriers 102 may be hollow to the end that they may be cooledby a suitable cooling medium which may be forced through suitableflexible conduits 200, shown in part in Figs. 9 and 14.

In the embodiment shown, the lugs L are short cylindrical pieces and arepositioned on diagonally opposite corners of the links at an angle ofsubstantially 27 degrees to the axis of the chain. Hence, it has beenfound advantageous to mount the electrode carry ing arms 104 at an angleof 27 degrees from the path of movement of the chain. The electrodes 100and 101 are mounted on the forward or left-hand ends of the arms 104,the rearmost ends of which are pivotally mounted on a pin 111, carriedinan upstanding bracket member 112, secured to the frame in any suitablemanner. The arms 104 are reciprocated or swung vertically in a mannerwhich will raise the electrodes clear of the lugs and thereafter bringthem down into contact with the lugs and increase the pressure of thelugs as the welding current softens the work, thereby insuring a mosteflective welding of the lugs to the link.

The electrode carrier assembly is rocked by a cam secured to the maindrive shaft 1. Pivotally mounted to the arms 104, intermediate theirends, is a block 115, through which a bar or rod 116 passes. The bar 116has a shoulder 117, which normally abuts the lower or bottom face of theblock 115. The uppermost end of the rod 116 extends above the block andis provided atits upper end with a washer 118 and an adjusting nut 119,while disposed between the washer and the block is a suitablecompression spring 120, which surrounds the rod and normally serves toretain the shoulder 117 of the rod 116 in position against the bottomsurface of the block 115.

When the welding electrodes are moved upward, the shoulder 117 is forcedagainst the block 115 and positively swings the arm 104 upward andcarries the electrodesja short distance above the chain, in whichposition the chain may be advanced without interfer ing with theelectrodes. When, however, the rod 116 is pulled downward to bring theelectrodes into contact with the lugs L, the arms 104 are moved downwarduntil the electrodes abut the work, and then, as the heating cur rent isapplied to the electrodes, further downward movement of the rod 116causes the compression of the spring 120, thereby increasing thepressure on the electrodes and forming the welds under compression.

The electrodes are operated from the main drive shaft 1. As shown inFig. 9, the rod 116 is pivotally connected as at 121, to an ear on thering 73, of the beam 74, which is swung or oscillated by the cam 72, asheretofore described. The downward movement .of the electrodes islimited by a suitable stop 123, carried in a frame member 124, and

through which the rod 116 passes. This pre- 8 vents excess pressure ofthe electrodes on the lugs and links and eliminates undue distort1on ofthe links. The stop 123 is adjusted so that the head 117 contacts withthelower surface of the block 115 when the electrodes have reached thelowermost position consistout with a good weld combined with the minimumamount of distortion of parts. Thereafter the continued downwardmovement of the rod serves only to. compress the spring 120 and has nofurther effect on the arm 104 or the parts being welded.

To conserve electrical energy, the welding current is supplied to thetransformer 108 only during the actual welding operation.

To this end one side of the input line leading .to the primary windingof the transformer 108 is connected by a line 130 to a movable contactarm 131, of a suitable switch 132.

The other contact 133 of the switch is con nected to the source ofcurrent supply.

The switch 132 may be of any suitable type. As shown in Fig. 9, themovable member 131 of the switch comprises a link pivoted to the frameat 134, and connected by continued movement to the beam 7 4, after the 1contact is made, will retain the switch inits active position withoutdamage to the parts thereof.

The lugs L are fed to the welding table 22 from a pair of tubes, 150, Fis. 9, 11 and 12. Lugs may be supplied to t e tubes 150 from a suitablefeed hopper, or manually, and are conveyed by the tubes to a pair ofchannels 151, in the welding table 22. The channels 151 are disposed onopposite sides of the 1 chain and are offset relative to each other sothat the lugs may align with the diagonal corners of the links, as shownin Fig. 11.

Slidably mounted in each channel 151 is a channel-shaped bar 152, eachof which carries a flat plunger bar 153, and is covered by a suitablecover plate 154.- Suitable plates 155 secured to the top of the table 22by bolts or screws 156 act to retain the channel bars and plungerswithin their respective grooves 151. The plungers and channel barsare'reciprocated by a-suitable mechanism, hereafter described.

When the chain is being fed across the table 22, the plungers-are drawnaway from the chain, and one end of a recess 157 in each of the plungersengages a pin 158 mounted in the corresponding channel bar and retainsthe bar in a withdrawn position. When the chain comes to rest and thepilot 70 enters the links, the plungers 153 are brought toward thelinks, and a spring 159 acts on pins 161,

which are integral with the channel bars,

and urges the channel bars against the links, thereby accuratelypositioning the links against the pilot.

The lugs L are fed from the tube 150 through slotted openings in thesides of the channel bars 152, and as the lugs are fed ,into the channelbars they underlie flat springs 165, carried by the cap 154, and whichserve to keep the lugs in contact with the channel bars and retard theirmovement, thereby preventing inadvertent displacement due to the speedof the mechanism. In this position the bottom face of each lug is in aplane slightly above the top of the link, where it is held by itsopposite ends, which are gripped between the side wall 152 and a leafspring 152a. As the plunger bars 153 are moved towards the link, eachplunger forces a lug from beneath its respective spring onto the link,where the lugs are immediately gripped by the electrodes 100 and 101.

When the lugs have been positioned on a link of the chain, the topsurface of the pilot is a short distance below the top of the lug,thereby preventing contact between the pilot and the electrode. However,as soon as the lugs are positioned and the electrodes-have gripped thelugs, the pilot 70 and plungers 153 are withdrawn and the weldingoperation takes place. Thereafter two more lugs are fed to the channelbarsand the chain is advanced, bringing another link into position to beengaged by the pilot, and the cycle of operation begins anew.

The lug feed, namely the plungers 153 and the r associated parts, isoperated from the main driving shaft 1. Each plunger 153 has, as shownin Fig. 11, a hook portion 170, which projects from the outer ends of respectlve channels 152. The hooks 170 embrace e rounded ends of arms 171,which are rlgldly secured to vertically extending shafts 173, (Figs. 9and 11) The shafts 173 extend verticallythrough the welding bed 22 andhave, rigidly secured to their lowermost ends, suitable horizontallyextending levers 176, which are .rigidly secured to a rock shaft 177.

The rock shaft 177 is operated by a cam mechanism which is associatedwith the main drive shaft 1. Rigidly secured to the rock shaft 177 is alever 178, which is pivotally connected to an end of a bar 180, theother end of which is forked as at 181, and embraces the main shaft 1.The bar carries a suitable roller 182, which is drawn into contact witha cam 183, rigidly carried by the main shaft 1, by a suitablecompression spring 184. As the shaft 1 rotates, the cam roller 182 willbe drawn into a recess 186 in the periphery of the cam, once for eachcycle of operation of the machine, thereby causing the lugs to be fed bythe plungers 153 to the chain link.

I will now summarize the timing of the various operations and steps ofmy improved method, with relation to the mechanism shown in thedrawings, reference being bad to the views showing the respective partsand also to the timing diagram of Fig. 16, in which the heavy linesindicate the action of the operations named thereon, and the light linesindicate idle conditions thereof. A complete rotation of a radial lineabout the center of the diagram indicates one cycle of operation of themachine, andat any given portion of said cycle the condition isindicated by respective heavy or light lines crossing the radius in thatposition.

We will assume that the parts are in the following positions: The feedlever 25 is in its rearmost position, and is raised to start the feed toengage the chain for a new purchase thereon. The lug feeding mechanismis idle. The electric current control or switch 131 is in an offposition. The electrodes 100 and 101 are leaving contact with the lug,while the electrode-carrying arms 104 are being raised free from thelinks which have previously been welded. The operation from thisposition is as follows:

The switch contacts are separated, thereby cutting the current from theelectrodes 100 and 101. The electrodes are then carried upwards,clearing the lugs. While the electrode-carrying arms 104 are moving totheir uppermost positions and start downward, the chain feeding arm 25functions to engage the feeding of the chain. The lug feed next comesinto operation to initiate the feeding movement of the lugs from thechannels to their relative positions on links of the chain. While thelugs are being fed, the chain feed stops. and the pilot snaps into placeto position a link of the chain. The channel members 152 also snap intoposition to retain the links against the pilot. The lug feed continuesin movement until the lugs arms 174, w ic are c nest d b link 1 t i cntagt w t the l g nd t e lug f ing mechanism begins to withdraw to clearthe electrodes. While the lug feeding mechanism continues to withdraw,the switch 132 .is turned on. The electrode arms 104 are then comingdown and pressure is applied through the spring 120 to the lugs, therebywelding the lugs to the links. The chain feed lever 25, during thistime, has started on its return movement to pick up another link. Thiscycle of operation is then complete, and the next feeding movement ofthe chain begins another cycle.

It will be observed that my method of welding two lugs to a linksimultaneously, with positive and negative electrodes engaging the lugsand the link carrying the current between them, produces a uniformwelding action on the two lugs, as well as allowing great speed ofoperation. Moreover, by reason of the constantly acting spring-pressureduring the welding operation-I obtain a very effective weld.' Likewise,I am able to feed the entire group of plain links, together with thelink to form the first of the next welded group, in a single cycle ofoperation of the mechanism, so that the machine goes on in repeatingcycles, one for every welded link, and without the loss of time forfeeding the various plain links. This method of operation is thereforerapid and effective.

I claim:

. 1. In the method of making tire chains, the steps of holding a link ofa chain by means engaging its interior, simultaneously feeding a pair oflugs on opposite regions of a link, simultaneously welding the lugsthereto while pressing them against the lugs and while supporting thelink on the opposite side. I

2. In the method of making tire chains, the step of electricallyweldinga pair of lugs on opposite regions of a link, while pressing theelectrode toward the lugs and supporting the link on' the opposite .sideto enable such 45 pressure to give a predetermined set to the last link.

3. The. method of applying lugs to a chain link, comprising holding alink by means occupylng its interior, placing a pair of lugs in contactwith a link so held, and bringing a pair of electrodes of oppositepolarity into contact with the lugs and applying current to pass fromone electrode through one lug, thence through the link to the other lugand thence to the other electrode.

4. The method of applying lugs to certain links of continuous chains,comprising feeding the chain by steps, holding each link by meansengaging its interior, bringing a pair of lugs into contact with thelink thus held, bringing a pair of electrodes into contact with i thelugs, supplying current to the electrodes, applying pressure between thelink and electrodes while the current is flowing, repeating suchoperation for a number of links, and

thereafter feeding atone time a length of link, comprising holding apair of lugs inv contact with a link and bringing a pair of electrodesinto contact with the lugs, supplying current to the electrodes, andapplying pressure between the link and electrodes to deform the linkwhile the current is flow- 1ng. V

7. The method of applying lugs to links of chains, comprising feedingthe chain by steps and applying a lug with each feeding operation, andthereafter feeding at one time a length of chain including severallinks.

8. In the method of applying lugs to links of chains, comprising feedingthe chain by steps corresponding to a single link and applying a lug toeach link, and feeding at one time a length of chain corresponding toseveral links and applying a lug to an end link of such group.

X 9. In the manufacture of chain having alternate groups of lugged linksand unlugged links, the steps of feeding sin 1e links to a weldingdevice, and thereafter ceding a plurality of links in a cycle ofoperation corresponding to the feeding of a single link.

10. In the manufacture of, chain having alternate groups of lu ged linksand unlugged links, the steps 0 feeding single links to a weldingdevice, feeding lugs to such links, electrically welding a pair of lugsto each of several links, and thereafter feeding a plurality of linkswithout the application of lugs thereto in a cycle of operationcorresponding to the feeding of a single link.

11. The method of making chain having alternate groups, of lugged linksand unlugged links, comprising periodically feeding a link at a time achain originally without lugs, welding lugs successively to successivelinks of the chain aid then feeding in one operation a plurality oflinks.

12. The method of making cross chains for tire chains, comprisingfeeding continuous chain of plain connected links, a link at a time,applying a pair of lugs to the opposite corners of each link so fed andelectrically welding them thereto, then after a number of links have hadlugs welded to them, feedlltl ing the chain a distance covering at leastfour links. this feed being eflected in a cycle of operationcorresponding to each of the preceding cycles, and then welding a pairof lugs onto opposite corners of the last link of the fed group whichlast link becomes the first welded link of the succeeding group andleaves at least three plain links between that group and the precedingwelded group, thereafter severing the chain through the mid-link of theplain groups to produce short chains each having an intermediate groupof lugged links and one or more plain links at each end thereof, andthereafter applying attaching devices to the terminal plain links ofsuch short chains.

In testimony whereof, I hereunto afiix my signature.

' MERRITT R. WELLS.

